@book{49130,
	author = {Kushner, Alexei and Lychagin, V. V.},
	title = {Contact geometry and non-linear differential equations /},
	publisher = {Cambridge University Press,},
	year = {2007},
	address = {Cambridge, UK ;},
	url = {http://www.loc.gov/catdir/enhancements/fy0704/2007273387-t.html}
}